An in-body image capturing device (camera unit) with high reliability is suggested. A camera unit (11) includes an image capturing unit that includes a lens (26) and a first illumination unit (27a) and is capable of being introduced into a body. The first illumination unit (27a) and the image capturing unit are housed in a casing (22) that is integrally molded with an integral light-transmitting body (22x) and an integral light shielding body (22y).